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Major mag. 7.7 earthquake - Samoa Islands Region on Tuesday, 1 September 1981

Major mag. 7.7 earthquake  - Samoa Islands Region on Tuesday, 1 September 1981
Date & time: Tuesday, 1 September 1981 09:29 UTC
Magnitude: 7.7
Depth: 25.0 km
Epicenter latitude / longitude: 14.96°S / 173.085°W (Samoa)
Nearest volcano: West Mata (73 km / 45 mi)
Nearby towns and cities:
134 km (83 mi) NE of Hihifo (pop: 800)
156 km (97 mi) SW of Satupa‘itea (pop: 0)
158 km (98 mi) SW of Vailoa (pop: 800)
167 km (104 mi) SW of Asau (pop: 6,600)
169 km (105 mi) SW of Mulifanua (pop: 4,500)
185 km (115 mi) SW of Afega (pop: 1,900)
Primary data source: USGS
Estimated released energy: 2.2 x 1016 joules (6219 gigawatt hours, equivalent to 5.4 x 106 tons of TNT or 334.4 atomic bombs!) [learn more]
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Data for the same earthquake reported by different agencies

Info: The more agencies report about the same quake and post similar data, the more confidence you can have in the data. It takes normally up to a few hours until earthquake parameters are calculated with near-optimum precision.
TimeMag. / DepthLocationSource
Thu, 1 Jan 00:00 UTCM
Note: for quakes of 2012 and earlier, our database often contains only records from USGS.

User reports for this quake

User reports estimate the perceived ground shaking intensity according to the MMI (modified Mercalli) scale.
There are no user reports for this quake yet. If you felt it or were nearby when it occurred, be the first to report it!

Aftershocks of the 7.7 quake: Samoa Islands Region, 1 Sep 1981 09h29

Show info about this
List of recorded aftershocks, latest first (172 quakes):
  • 30 Aug 1983 08:50 UTC
    | M 6.1 |
    38.7 km (24 mi) depth
    |
    222 km (138 mi) distance
    | USGS | Strong mag. 6.1 earthquake - Samoa Islands Region (Tonga) on Tuesday, 30 August 1983
  • 15 Aug 1983 19:44 UTC
    | M 5.5 |
    181.5 km (112.8 mi) depth
    |
    283 km (176 mi) distance
    | USGS | Details
  • 27 Jul 1983 21:13 UTC
    | M 5.0 |
    33 km (20.5 mi) depth
    |
    245 km (152 mi) distance
    | USGS | Details
  • 29 Jun 1983 03:29 UTC
    | M 5.2 |
    33 km (20.5 mi) depth
    |
    53 km (33 mi) distance
    | USGS | Details
  • 21 Jun 1983 11:36 UTC
    | M 5.1 |
    33 km (20.5 mi) depth
    |
    63 km (39 mi) distance
    | USGS | Details
  • 15 Jun 1983 06:07 UTC
    | M 5.5 |
    33 km (20.5 mi) depth
    |
    66 km (41 mi) distance
    | USGS | Details
  • 05 Jun 1983 16:26 UTC
    | M 5.3 |
    33 km (20.5 mi) depth
    |
    109 km (68 mi) distance
    | USGS | Details
  • 05 Jun 1983 13:59 UTC
    | M 5.3 |
    33 km (20.5 mi) depth
    |
    157 km (97 mi) distance
    | USGS | Details
  • 05 Jun 1983 13:23 UTC
    | M 5.1 |
    33 km (20.5 mi) depth
    |
    123 km (76 mi) distance
    | USGS | Details
  • 01 Jun 1983 10:58 UTC
    | M 6.1 |
    33 km (20.5 mi) depth
    |
    87 km (54 mi) distance
    | USGS | Strong mag. 6.1 earthquake - Samoa Islands Region on Wednesday, 1 June 1983
  • 01 Jun 1983 01:59 UTC
    | M 6.6 |
    179.6 km (111.6 mi) depth
    |
    283 km (176 mi) distance
    | USGS | Strong mag. 6.6 earthquake - Tonga on Wednesday, 1 June 1983
  • 29 May 1983 22:07 UTC
    | M 5.4 |
    287.2 km (178.5 mi) depth
    |
    206 km (128 mi) distance
    | USGS | Details
  • 21 Feb 1983 17:46 UTC
    | M 5.3 |
    33 km (20.5 mi) depth
    |
    287 km (178 mi) distance
    | USGS | Details
  • 26 Jan 1983 18:55 UTC
    | M 5.4 |
    41 km (25.5 mi) depth
    |
    69 km (43 mi) distance
    | USGS | Details
  • 24 Jan 1983 04:28 UTC
    | M 5.3 |
    33 km (20.5 mi) depth
    |
    91 km (56 mi) distance
    | USGS | Details
  • 08 Jan 1983 11:21 UTC
    | M 6.4 |
    33 km (20.5 mi) depth
    |
    55 km (34 mi) distance
    | USGS | Strong mag. 6.4 earthquake - Tonga (Samoa) on Saturday, 8 January 1983
  • Show all

Map of aftershocks

Significant earthquakes in the same area since 1900

Major mag. 7.7 earthquake - Samoa Islands Region on Tuesday, 1 September 1981
 

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